Puffed food starch product

ABSTRACT

The present invention includes puffed food starch material snack, in particular starch material from grains, having an improved crispy texture and a more aesthetic appearance and methods for preparing them. In general terms, the products are snack chips, cakes, crackers or the like, made from food starch material. Preferably, the starch material is provided primarily in the form of individual kernels or pellets of a cereal grain, such as rice, corn, wheat, rye, oats, millet, sorghum, barley, buckwheat, or mixtures thereof. Quantities of other food starch materials may also be employed as a co-mixed constituent, or the primary source of bulk starch material, for example potato starch material. A quantity of the grain is puffed (expanded) in a manner which forms a snack product of considerable crispiness, lightness, and unique texture to both the mouth and eye.  
     According to a method of making the puffed food starch material product of the present invention, a puffing chamber is provided having inner surfaces and a chamber volume. A bulk amount of the food starch material is placed into the puffing chamber. The bulk amount of food starch material is caused to volumetrically expand. The expanding food starch material is constrained in its expansion in at least a first dimension, while permitting expansion of the bulk amount in at least a second dimension.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of application Ser. No.09/384,015, filed Aug. 26, 1999, which is a divisional of applicationSer. No. 09/281,991, filed Mar. 29, 1999, now U.S. Pat. No. 6,569,481.

TECHNICAL FIELD

[0002] This invention relates generally to improved puffed food starchproducts made from cereal grains or other food starches, forming suchproducts into various shapes, and the methods for their manufacture.More particularly, the present invention relates to puffed-rice snackswith improved crispiness, and appealing visual and physical texture, andprocesses of preparing such snacks.

BACKGROUND OF THE INVENTION

[0003] Snacks have long been a household staple around the world andrange from treats to dietary supplements. However, not too long ago anutrition trend found chocolates, candies, ice cream, and othernaturally and artificially sweetened confections, as well as potatochips, pretzels, corn chips, and the like, being replaced by morehealthy products. The terms “low fat,” “no-fat,” and “light” have becomethe watch words of the health conscious in the '90s. The trend has seenthe popularity of puffed snacks, sometimes referred to as popped grainsnacks and especially those made of corn and rice, steadily climb.

[0004] Very successful products have been made in the form of cakesgenerally made of puffed corn or rice. While these products had aheretofore acceptable amount of crispiness, they suffered from anunpleasant texture, usually nearest the core of the cake, resulting inthe product sticking in teeth. The products are hockey puck-shaped(uniform in all three dimensions) and lack the appealing visual textureof conventional snack foods. The size of these snack cakes is alsorelatively large in size (approximately a three to four-inch disk-shapedcake). This size, as a single portion, can lead to a substantial amountof waste for some consumers, especially children. To address the problemof waste, a “mini-cake,” or smaller version of the original cake (abouta one to two-inch disk-shaped cake or cracker) was introduced. Theproblems of texture and appearance, however, remained.

[0005] Examples of methods for making conventional grain cake productsare disclosed in the described methods of U.S. Pat. No. 4,888,180 to Wu.These cake-forming devices are most frequently used with rice as thecereal grain since rice is capable of relatively easy expansion into aself-supporting cake. Statistics show that the availability andversatility of rice have not only made it an industry favorite, but aconsumer favorite as well. The annual world rice harvest in the early1990s exceeded 510 million metric tons, an increase of about 30 percentover the average during the period from 1979 to 1981. Rice grains areextensively used as human food, constituting the principal food ofalmost one-half the human race. The leading rice producers are China,with 36 percent of world output in the early 1990s, and India, with 22percent. In the United States, production averaged close to 7 millionmetric tons, with Arkansas, California, Louisiana, and Texas being theleading rice-producing states.

[0006] Rice puffing and, in general, cereal puffing (or cereal popping)methods are well established in the prior art. Generally, methods knownin the art rely primarily on a moisture content in the grains forpuffing. The moisture content can be varied by many processes, such as,drying, cooking, parboiling, and tempering. Examples of attemptedimprovements in processing methods are described in U.S. Pat. No.4,281,593 to Gevaert, U.S. Pat. No. 4,328,741 to Yoshikazu, and U.S.Pat. No. 4,667,588 to Hayashi.

[0007] There are two generally practiced methods for expanding orpuffing grains: (1) heating the kernels of grain until they becomeextensible (i.e. until the starch becomes amorphous or flowable) atwhich point further heating permits evaporation of moisture (andout-gassing of some minor amounts of other gases entrained in the grain)which causes expansion (bubble formation) in the amorphous starch; (2)heating the grain kernels to a flowable state at atmospheric pressure,then suddenly reducing the pressure (partial vacuum) again permittingenhanced vaporization and out-gassing, and again causing expansion(bubble formation) in the amorphous starch; and (3) heating the grainkernels to a flowable state in a chamber where pressure is permitted (orcaused) to build, then suddenly reducing the pressure to atmospheric,permitting enhanced vaporization and out-gassing and again causingexpansion (bubble formation) in the amorphous starch.

[0008] This latter method is most conventionally used to make rice cakesof both the larger and “mini” sizes. This latter method is carried outin what is commonly referred to as rice popping machines. These machinesprovide a chamber defined by heated chamber walls. Once the pre-puffedgrain is placed in the chamber, it is closed to a pressure seal. Thefood starch is heated by contact with the chamber walls. The amount offood starch, i.e. the amount of grain kernels loaded into the chamber,relative to the volume of the chamber, and amount of expansion, causethe puffed product to generally conform in all three dimensions to theshape of the chamber.

[0009] One problem with conventional rice popping processes is that thefilling of the entire volume of the popping chamber upon expansion maylimit the bubble size formed, or full expansion of the bulk amount ofthe food starch, or both. This may account for a less than fully crispedproduct and a teeth-sticking texture of the resulting rice cake. It iscertainly responsible for the hockey puck-shape of the product, whichheretofore was thought to be desirable.

[0010] Another problem which exists in use of rice popping equipment istrying to balance providing sufficient time to present good conditionsfor full expansion of the food starch, while at the same time trying tominimize chamber residence time to achieve high production rates. Todate, this balance has produced the conventional rice cakes discussedabove.

[0011] It is well known that the degree and ease of puffing is affectedby many factors such as: the type of grain, the type of preprocessing(e.g. milling), the condition of the grain (e.g. moisture content), andthe type of starch contained in the grain. Another advancement inpuffing food starch is to puff food starch which has been floured, andto extrude it into a discrete size and shape. Such extruded pieces arecooled and dried to a state of desired moisture content and hardness foracceptable handling and storage. To date, such puffing has been limitedto oven puffing or deep frying. The resulting products, however, arerelatively uniform throughout the snack piece, and provide a monolithictexture to the mouth when eating them. The same can be said for theproducts made from the more conventional process of extrusion puffing.

[0012] The inventor is unaware of a cake-type product ever beingattempted using such pelletized stock. Further, it appears that prior tothe present invention, it has never been contemplated to employ such apelletized pre-product in a rice popping machine or related process.

[0013] In sum, despite the improvements being made in the field ofmaking puffed snack cakes from food starches, in particular rice grain,insufficient attention has been given to improving the overall visualand physical texture (e.g. crispiness) and appearance of the product.The present invention addresses these issues as well as solving theproblems discussed above and providing other advantages which willbecome apparent to those skilled in the art upon reading theaccompanying specification and claims.

SUMMARY OF THE INVENTION

[0014] The present invention provides puffed-food starch snacks havingan improved crispy texture and a more aesthetic appearance and methodsfor preparing them.

[0015] In general terms, the products are snack chips, cakes, crackersor the like, made from food starch. Preferably, the starch material isprovided primarily in the form of individual kernels or pellets of acereal grain, such as rice, corn, wheat, rye, oats, millet, sorghum,barley, buckwheat, or mixtures thereof. Quantities of other foodstarches may also be employed as a co-mixed constituent, or as theprimary source of bulk starch material, for example, potato starch. Aquantity of the food starch is puffed (expanded) in a manner which formsa snack product of considerable crispiness, lightness, and uniquetexture to both the mouth and eye.

[0016] According to one aspect of the invention, a puffed snack productcomprises a puffed starch body having a generally regular perimetricalshape, and opposed upper and lower surfaces. At least one of the upperand lower surfaces has a substantially wavy contour such that it appearsas though individual kernels of grain are joined to one another. It ispreferred that the substantially wavy surface of the starch bodycomprises hills and valleys, noted by the rise and fall of the surfacealong a parallel plane.

[0017] In a preferred embodiment, the puffed snack product is comprisedprimarily of rice starch, but may further include puffed corn starch,puffed wheat starch, puffed potato starch, or the like.

[0018] In other presently preferred embodiments, the puffed snackproduct may be comprised primarily or predominantly of puffed cornstarch, puffed wheat starch, or puffed potato starch, with combinationsof other such grains possible. Presently, a preferred perimetrical shapeof the food product is generally circular, hence a rounded cake in twodimensions. Alternatively, other embodiments may include a perimetricalshape which is generally triangular, square, rectangular, or any othersuch geometric or fanciful shape as may be thought at the time to haveconsumer appeal or processing, handling, or packaging advantages.

[0019] According to another aspect of the invention, the bulk cakeproduct is comprised of an amount of food starch in the form of aplurality of individual whole kernels of grain, puffed together. Atleast a portion of these whole kernels may be rice kernels, wheatkernels, or both, and may additionally include corn grits.

[0020] According to another aspect of the invention, the cake or snackbody is formed from a bulk amount of food starch comprised of aplurality of individual pellets (formed from starchy flour) all puffedtogether. Such pellets are preferably made from rice flour, wheat flour,corn flour, potato flour or the like, and may additionally include corngrits. A sufficient amount of pellets (and corn grits, if desired)capable of becoming amorphous in the puffing chamber should be provided,such that all of the pellets and grits touch at least one other pelletor grit after becoming amorphous.

[0021] According to another aspect of the invention, a puffing chamberis provided having inner surfaces and a chamber volume. A bulk amount ofthe food starch is placed into the puffing chamber. The bulk amount offood starch material is caused to volumetrically expand. The expandingfood starch is constrained in its expansion in at least a firstdimension, while permitting expansion of the bulk amount in at least asecond dimension.

[0022] The step of constraining expansion may additionally includeconstraining expansion of the bulk amount in a third dimension. Theconstraining may achieve a defining of the general shape of the finalproduct in the first dimension, or in both the first and thirddimensions. The defined shape may be provided by, in one particularembodiment, constraining expansion with certain of the inner surfaces ofthe puffing chamber. Preferably, for the snack cake disclosed in theexample below, the unconstrained second dimension is height.

[0023] Another method of the present invention includes predeterminingthe bulk amount of food starch material to be placed into the chamber.The predetermining should provide a sufficient amount of whole kernels(or corn grits, if desired) capable of becoming amorphous, such that allof the kernels and grits touch at least one other kernel or grit afterbecoming amorphous.

[0024] Where pellets are used, the method may further include formingthe pellets generally to the size of a whole kernel of grain selectedfrom the group of grains including rice, wheat, barley, oats, rye, andcorn.

[0025] Another aspect of the invention provides for puffing a foodstarch capable of becoming amorphous into a food starch product, whereinthe food starch is first floured then pre-gelatinized in an extruderunder a pressure and temperature. The food starch is then extruded andcut into pellets. The pelletized food starch is placed into a puffingchamber where increasing the pressure and the temperature in the chambercauses the pelletized food starch to become amorphous. By quicklyreducing the pressure in the chamber, the amorphous starch pelletsexpand.

[0026] The pellets are believed to provide superior puffing (at leastrelative to a given time and temperature cycle in mass production) towhole kernels. While presently unproven, the advantages are believed tobe that: (1) the pellets are pre-gelatinized and may allow more of theheat energy (in the given cycle time or amount of thermal energy) tocontribute to water vaporization and bubble formation (as opposed toproviding energy to accomplish a greater crystalline phase change) thanin a grain kernel; (2) the pelletized rice has been pre-floured, hencethe mechanical and physical boundaries of the cellular structure havealready been broken down leading to a more uniform expansion with less(heat) energy required to break down the cellular structure; and (3) theuniform pellet structure has a more uniform distribution of both starchand moisture for improved crisp puffing.

[0027] According to another aspect of the invention, the extruded foodstarch pellets may be cooled under sufficiently controlled (slowly)parameters to reduce stress in the pellet (i.e. an annealing of thepellets). This should reduce the energy required for possible annealingin the popping chamber. Also, the slow drying should enhance enduranceof further handling without fracturing. The extruded pellets should beprovided with sufficient drying to enhance shelf life and to preventpellets from sticking together in storage.

[0028] It is also possible that, once gelatinized, the pellets arecooled in such away as to reduce recrystallization of the starch. Thismay also assist in puffing in that for a fixed amount of energy input,energy is not wasted unduly on annealing in the puffing chamber.However, such a cooling may be at odds with the slow cooling for stressreduction. While one type of cooling may be used as a trade off for theother, stress reduction presently looks to be the preferred goal.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In the drawings,

[0030]FIG. 1 is a cut-away side view depicting a puffing machine used inthe present invention in a completely open position;

[0031]FIG. 2 is a similar view of the puffing machine of FIG. 1 showingthe placement of food starch within a couple of chambers;

[0032]FIG. 3 is a similar view of the puffing machine of FIG. 1 showingthe sealed chambers;

[0033]FIG. 4 is a similar view of the puffing machine of FIG. 1 justsubsequent to breaking the seal on the chambers;

[0034]FIG. 5 is a similar view of the puffing machine of FIG. 1 showingthe upper mold fully retracted;

[0035]FIG. 6 is a similar view of the puffing machine of FIG. 1 showingthe final product being ejected from the mold;

[0036]FIG. 7 is a top view of a supply plate for the present invention;

[0037]FIG. 8 is a perspective view of a puffed food starch product madein accordance with one embodiment of the present invention;

[0038]FIG. 9 is a top view of a puffed food starch product as shown inFIG. 8;

[0039]FIG. 10 is a bottom view of a puffed food starch product as shownin FIG. 8;

[0040]FIG. 11 is a first side view of a puffed food starch product asshown in FIG. 8;

[0041]FIG. 12 is a second side view of a puffed food starch product asshown in FIG. 8;

[0042]FIG. 13 is a third side view of a puffed food starch product asshown in FIG. 8;

[0043]FIG. 14 is a fourth side view of a puffed food starch product asshown in FIG. 8;

[0044]FIG. 15 is a perspective view of another puffed food starchproduct made in accordance with one embodiment of the present invention;

[0045]FIG. 16 is a perspective view of another puffed food starchproduct made in accordance with one embodiment of the present invention;

[0046]FIG. 17 is a perspective view of another puffed food starchproduct made in accordance with one embodiment of the present invention;

[0047]FIG. 18 is a flow chart illustrating an embodiment of the presentmethod for producing a puffed food starch product;

[0048]FIG. 19 is a flow chart illustrating another embodiment of thepresent method for producing a puffed food starch product usingpelletized food starch; and

[0049]FIG. 20 is a flow chart generally illustrating the operation ofthe puffing machine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0050] While the invention is susceptible of embodiment in manydifferent forms, this disclosure will describe in detail preferredembodiments of the invention with the understanding that the presentdisclosure is to be considered as an exemplification of the principlesof the invention and is not intended to limit the broad aspect of theinvention to the embodiments illustrated.

[0051] Product

[0052] The puffed or popped food starch products of the presentinvention provide a number of advantages over prior puffed food starchcake or cracker products. It is believed that the products are lighter,crispier, and have a more appealing visual texture as well as texture tothe mouth when consumed. In some cases products made in accordance withthe invention are believed to have a more natural, unprocessedappearance, as illustrated in FIGS. 8-17.

[0053] However, the wavy, natural appearance provides functionaladvantages over the prior art as well. The undulating surface allowssnack dips to be more easily scooped, much like a potato chip or cornchip, than hockey puck-shaped cakes. Additionally, the present productmay be sprinkled with flavoring during manufacturing, including suchsavory flavors as barbeque, sour cream, cheese, garlic and onion, andmost any other popular snack flavor. The highly textured surfaceprovides longer retention of granular or crystalline flavor coatings.Additionally, because the top and bottom surface areas of each chip arelarger than a standard flat surface of prior art cakes, a greater amountof flavoring may be applied. More flavoring may improve the overallflavor of a product that has enjoyed past commercial success.

[0054] Products according to the invention may be in the form of a snackchip, cake, or cracker. They can be made from individual kernelsaccording to certain aspects of the invention and from individualpellets of extruded food starch material according to other aspects ofthe invention. Disclosed herein are cakes made from a cereal grain, suchas rice, corn, wheat, rye, oats, millet, sorghum, barley, buckwheat, ormixtures thereof. A quantity of the grain is puffed (expanded) in amanner which forms a snack product of considerable lightness andcrispiness over previous puffed-grain snacks.

[0055] The puffing phenomenon results from the sudden expansion of watervapor (steam) from moisture held within the starch material of thegranule (and some out-gassing). The particle is fixed in its expandedstate by the dehydration resulting from the rapid diffusion of watervapor out of it. The moisture level is considered an important factor inpuffing grain. Before puffing, the grain or pellet preferably should bemaintained at no less than 3% moisture in order to achieve the desiredextent of puffing and crispness of the final product. The preferredembodiment has a moisture content which falls within the range of fromabout 8% to about 18% (by weight) moisture, with about 8% to about 13%(by weight) being more preferred, and about 10% to about 12% being themost preferred moisture content. Moisture contents outside of the 8-18%range may cause a decreased puffing on the one hand, and collapse of analready puffed product on the other hand.

[0056] Rice grain is preferred for many reasons, including itscapability to expand with relative ease into a self-supporting cakeproduct. FIGS. 8-14 show various views of one embodiment of a snack cakeaccording to the present invention. The puffed snack product of thepresent invention comprises a puffed starch body 10 having a generallyregular perimetrical shape, and opposed upper and lower surfaces 12, 14.The perimetrical shape of body 10 is circular. Other shapes, arecontemplated, for example, other geometric shapes: triangular, square,rectangular, etc., and fanciful shapes may provide particular advantagesin some instances. FIGS. 15-17 show food starch products with surfacevariations.

[0057] Referring to FIGS. 8-14, the upper surface 12 and the lowersurface 14 have a substantially wavy contour, and each surface 12, 14has a general appearance which permits visual discrimination betweenindividual kernels of grain 16 as they are joined to one another. It ispreferred that the substantially wavy surface of the starch body 10comprises hills 17 and valleys 18, noted by the non-uniform rise andfall of the surfaces 12, 14.

[0058] While the preferred starch body 10 is comprised primarily ofrice, it may further include corn, wheat, potato, oats, rye, barley,buckwheat, or any combination of these or other suitable sources ofpuffable food starch. Hereafter, the terms “good” or “goods” areintended to describe starch-bearing materials, including cereal grains,seeds, tubers, and the like, which are used in the present process tomake up the food starch of the starch bodies such as body 10 or inmaking up the bulk amount of food starch placed in the puffing chamber.Where applicable, these goods may be supplied in the form of groundflour, whole kernels, or in a pelletized form. Mixtures of goods in theform of flour, or mixed whole kernels or mixed pellets may also be usedin accordance with the present invention, with varying results.

[0059] With respect to flour and whole kernels, single goods or mixturesof goods may be used to create a suitable puffable food starchcomposition. As rice is the preferred food starch in the disclosedembodiment of body 10, it should be understood it will be the preferredpredominant good used in mixtures for many of the disclosed methods. Apredominantly rice flour mixture may contain rice flour within the rangeof about 51% to 100% by weight. Similarly, predominantly corn flourmixture would be predominantly corn flour (i.e., at least 51% byweight). The remaining percentage, up to 49% by weight, may be made upof any one or more of other floured goods. This is equally true for amixture of predominantly rice grain, or predominantly corn grit (i.e.,cracked corn). It should be noted that moisture content of therespective starch constituents is counted in its weight percentage.

[0060] Pellets are more variable than either flour or whole kernels. Thepellets themselves may be made from a mixture of goods from a flourform, and the entire composition may be comprised of several differentkinds of pellets. For instance, “A” pellets may be formed from a mixtureof 75% by weight rice flour and 25% by weight corn flour, while “B”pellets may be formed from 60% by weight rice flour and 40% by weightpotato flour. A first recipe may call for 50% by weight of “A” pelletsand 50% by weight of “B” pellets, while a second recipe may require 90%by weight “A” pellets and only 10% by weight of “B” pellets. The variouscombinations are nearly infinite.

[0061] Of the three forms of goods disclosed, pellets are a preferredform, according to a separate aspect of the invention. Pellets provideexcellent textural features (e.g., crispiness, contour, etc.), produce ahigh-quality puffed product, and allow more precise control of moisturecontent. While rice is the preferred good for the pelletized form in thepresent invention, other embodiments of the puffed snack product may becomprised primarily of corn, wheat, or a puffed potato starch, withcombinations and other such grains (or starches from sources other thangrains) also possible.

[0062] Part of what gives the present invention its unique surfacecontour is the composition of the bulk food starch. The various goodswill all have different expandability, partly dependent upon moisturecontent and partially due to the differing starch characteristics,compositions, or pre-processing (such as pre-gelatinization). Byassembling a bulk food starch of predominantly rice (either flour, wholekernels, or pellets) interspersed with, for instance, the preferred corngrits, the puffed product will have natural surface and texturevariations due to varied expansion. Therefore, to facilitate this effectin the present invention, at least a portion of the bulk food starch incertain embodiments will be enhanced by the inclusion of corn gritswhich do not expand as much as rice pellets or kernels.

[0063] Referring again to FIGS. 8-14, regardless of the good(s) or formused, according to one aspect of the invention, the product has agenerally predefined perimetrical shape. Preferably, the perimetricalshape of the food product is one that is appealing to consumers and issuitable for use in a chamber-type popping machine. Applicant has founda circular shape to meet both of these requirements. It is also believedthat there may be textural advantages of the circular shape.

[0064] In order to form the preferred product, which is more easilyunderstood with reference to the described methods, a sufficient amountof whole kernels or pellets (and corn grits) capable of becomingamorphous, should be provided such that all of the whole kernels orpellets (and grits) touch or contact at least one other whole kernel orpellet (or grit) after becoming amorphous. In other words, the bulk foodstarch is capable of melting into a single flowable mass. This meansthat the amount of bulk food starch used for making the presentinventive product is an important feature, as discussed below.

[0065] The area of contact between two or more of the kernels or pelletsform a connective boundary after they become flowable. This boundarydefines the area of connection between kernels or pellets. The preferredpuffed product is most readily broken apart at these boundaries, asopposed to breaking within the body of the puffed kernel or pellet. Thisadds to the aesthetic appearance of the product according to the presentinvention. Prior art grain cakes are typically comprised of indistinctor less distinguishable boundaries between puffed kernels, breakingalong less visually determinable lines.

[0066] Another textural distinguishing aspect of the present inventionover the prior art relates to the product thickness. The preferredproduct is typically a single layer, approximately one grain thick. Thishelps insure contact between individual kernels, pellets, and gritsoccurs on no more than two dimensions (i.e., primarily side-to-sideconnection). This, in turn, insures the added eating textural appeal ofindividual kernels or pellets in each puffed product. Conversely, theprior art cakes are several grains thick, causing three dimensionalcontact (i.e., side-to-side and top-to-bottom connections). Suchthree-dimensional contact removes the added aesthetic and texturalcrispiness and appeal of the individual kernels or pellets within thecake. This again relates to the amount of bulk food starch relative tothe puffing chamber volume and resting area.

[0067] Processes

[0068] In many prior art processes, an amount of food starch (in wholekernel form only) is added to a puffing chamber so that upon expansionthe food starch fills the entire chamber. The result is a puffed productconformed exactly to the size and shape of the chamber, in substantiallythe form of a disk. This is very different than the present invention.

[0069] A preferred method of making the puffed food starch product ofthe present invention, illustrated in FIG. 18, utilizes a bulk amount ofa previously described food starch. The disclosed method begins byproviding a puffing chamber having inner surfaces and a chamber volume,and then placing a bulk amount of the food starch material into thepuffing chamber. Generally speaking, the bulk amount of food starch iscaused to volumetrically expand. In other words, the bulk food starch ispuffed to several times its original size.

[0070] Puffing machines (usually having a plurality of chambers each)are widely known and understood by those skilled in the art. A suitablepuffing machine is manufactured by REAL FOODS PTY, LTD. of St. PetersNSW, Australia. Referring to FIGS. 1-6, puffing chamber 20 is shown,generally, having an opening 21 on ring mold 22, upper mold insert 24(attached to an upper base 25), and lower mold insert 26 (attached to alower base 27). Each of these components may be slidably movable onguide pins 28, though ring mold 22 is typically fixed. The mold inserts24, 26 (via bases 25, 27) may be actuated hydraulically, pneumatically,or in any other suitable manner. As shown in FIGS. 2 and 3, mold inserts24, 26 enter opening 21 to form the inner surfaces of the puffingchamber.

[0071] The present preferred method requires constraining the expansionof the bulk amount of food starch in at least a first dimension, whilepermitting expansion of the bulk amount in at least a second dimension.In other words, the food starch is capable of expanding to its fullvolumetric potential (taking into account moisture content of the foodstarch, temperature of the chamber, and the forces of gravity), whilebeing prevented from expanding in one of either height, width, or depth.For example, if the height of the puffed product is constrained, thenthe width and depth of the puffed product proportionately increase.Where two dimensions are constrained, the third will compensate toachieve total volume expansion. At no time is the total volumetricexpansion of the puffed product constrained by the inner surfaces of thepuffing chamber, while dimensional expansion is constrained. Preferably,this may be achieved by predetermining the proper amount of the bulkamount of food starch placed into the puffing chamber relative to thetotal volume of the chamber in an unsealed (puffing) condition. Priorart processes attempt to completely fill the chamber (at least uponpuffing).

[0072] Using the puffing chamber for dimensional constraining may beachieved by defining a general shape of the product (as discussedpreviously) in the first dimension, or in both the first and thirddimensions. The constrained shape may be provided by, in one particularembodiment, constraining expansion with the inner surfaces of thepuffing chamber.

[0073] Balanced against the unconstrained volumetric expansion aspectsof the present invention (i.e., properly sizing the bulk amount of foodstarch placed into the puffing chamber) is the necessity to produce asingle, unitary product from the puffing chamber. With these competinginterests in mind, the present method may further include predeterminingthe bulk amount of food starch to be placed into the chamber, such thatthere is a sufficient amount of whole kernels or pellets (or corn grits)that all of the kernels or pellets (and grits) touch at least one otherkernel or pellet (or grit) after becoming amorphous.

[0074] While the exact mechanism of how the food starch bonds togetherin the puffing chamber is not fully understood, referring to FIG. 20, itis believed that a melt occurs, or at least a softening orgelatinization of the food starch. In a preferred embodiment of theinvention, the puffing chamber 20 is heated to a temperature of about475° F. (about 246° C.). Puffing machines, as well as individual puffingchambers, however, can vary greatly from one to another. Due to suchdifferences, and any other prevailing conditions which may exist (e.g.,the amount and type of food starch and its preprocessing history), thechamber temperature may range from about 350° F. (about 177° C.) toabout 550° F. (about 288° C.), including any combination orsub-combination of ranges within this range. As the chamber is sealedand the food starch is heated, the internal pressure of the chamberincreases, though a final pressure has not been measured. No additionalpressure is added to the chamber in the preferred embodiment, but may beimplemented for alternative embodiments.

[0075] Referring to FIG. 7, a supply plate 30 is shown. Supply plate 30is shown having seven (7) openings 32, but may contain more or less tosuit particular manufacturing needs. Openings are preferably about 0.563inches diameter by about 0.591 inches deep (about 0.147 cubic inches) toallow a sufficient amount of bulk food starch to pass through forpuffing an approximately two inch (2″) product, but these dimensions mayvary for larger or smaller products. The volume of opening 32 determinesthe amount of food starch to be added to each chamber. Each opening 32corresponds to a chamber 20 of the puffing machine. As supply plate 30moves across the open ring mold 22, it deposits the predetermined amountof bulk material filling each opening volume into the chamber 20, torest on lower mold insert 26. Supply plate 30 is then retracted.

[0076] The chamber is closed as shown in the sequence of FIGS. 2-5, andthe bulk food starch is heated to an amorphous or extensible state.After an approximate 5.25 to 6.75 second heating cycle time, upper moldinsert 24 raises to release pressure in chamber 20, as shown in FIG. 4.Then upper mold insert 24 completely raises and lower mold insert 26raises to become flush with the upper surface of ring mold 22, as shownin FIG. 6. Finally, supply plate 30 returns to make a subsequentdeposit, pushing the puffed food starch products to a discharge chute(not shown) in the process.

[0077] The amount of food starch used in the present invention is lessthan that used in prior art processes. A relationship exists between themass of food starch used and the expansion of the final product, alsotaking into consideration the chamber volume (about 0.79 cubic inches inthe present invention), cycle time, and chamber temperature. Basically,the expanded food starch should not be constrained by the chambervolume, as discussed above. Another consideration, however, is theplacement of the food starch within the chamber. If the food starch isthick or mounded on top of itself, then expansion of the food starch asa whole will be diminished. Thinly spread food starch will tend to puffmore completely.

[0078] Where pellets are used in the present invention, it is consideredto be within the knowledge of those skilled in the art to preparesuitable pellets. The J. R. SHORT COMPANY, Chicago, Ill., manufacturessuch a rice pellet. Basically, referring to FIG. 19, beginning with afloured food starch, the starch is gelatinized in an extruder under apressure and temperature. The food starch is then extruded and cut,forming individual pellets. The pellets, in the preferred embodiment,are formed generally to the size of a whole kernel of grain. The grainsize can be selected from the group of grains including rice, wheat,barley, oats, rye, corn, etc. The extruded food starch pellets may becooled sufficiently (i.e., slowly) to substantially reduce any stress inthe pellet, and to provide sufficient drying to provide good shelf lifeand prevent extruded food starch pellets from sticking together instorage.

[0079] In another preferred embodiment of the present method, Applicantfound advantages in pelletizing the food starch material, and thenplacing an amount of the pelletized food starch into the puffingchamber. The amount may be as little as a single pellet, or as many assuitable for the chamber size. The pellets within the chamber are thencaused to volumetrically expand and form a suitable cake or chip.

[0080] Another major advantage of the use of pellets over whole kernelsis that the pellets need not be tempered prior to puffing. Tempering isa process whereby the whole kernels are tumbled in a high moistureatmosphere (frequently steam is used). This is not necessary forpellets. The moisture content of the pellets is controlled atmanufacture, most preferably within the range of about 10% to about 12%(by weight). Additionally, the tempering process is used to increase thepuffability of the kernels, as described above. Pelletization appears toprovide sufficient enhancements to puffability to negate the need fortempering.

[0081] While specific embodiments have been illustrated and described,numerous modifications are possible without departing from the spirit ofthe invention, and the scope of protection is only limited by the scopeof the accompanying claims.

What we claim is:
 1. A puffed snack product comprising: a unitary puffedstarch material body, wherein said puffed starch material body comprisesa plurality of individual puffed pellets formed from a starch powder. 2.The puffed snack product according to claim 1 wherein the puffed snackproduct is at least one of chips, cakes, and crackers.
 3. The puffedsnack product according to claim 1 wherein said plurality of puffedpellets comprise at least one of puffed rice pellets, puffed wheatpellets, puffed corn pellets, puffed potato pellets, and mixturesthereof.
 4. The puffed snack product according to claim 1 wherein thestarch powder comprises at least one of a flour of corn, wheat, potato,oats, rye, barley, buckwheat, and mixtures thereof.
 5. The puffed snackproduct according to claim 1 wherein said puffed starch material bodycomprises at least two types of said individual puffed pellets, whereineach type of pellet has been expanded by a different degree.
 6. Thepuffed snack product according to claim 1 wherein each of said puffedpellets has an outer surface and includes a location on the outersurface for contacting another of said puffed pellets.
 7. The puffedsnack product according to claim 6 wherein each of said puffed pelletsis in contact with another of said puffed pellets in no more than twodimensions.
 8. The puffed snack product according to claim 1 wherein thepuffed snack product comprises a single layer.
 9. The puffed snackproduct according to claim 8 wherein the single layer is approximatelyone pellet thick.
 10. The puffed snack product according to claim 1wherein each of said puffed pellets is of a size of a whole kernel of agrain selected from the group consisting of rice, wheat, barley, oats,rye, and corn.
 11. The puffed snack product according to claim 1 whereineach puffed pellet is formed from a gelatin of the starch powder. 12.The puffed snack product according to claim 1 wherein said puffedpellets included a moisture content of at least about 3% by weight priorto being puffed.
 13. The puffed snack product according to claim 1wherein said puffed pellets included a moisture content in the range offrom about 10% and about 12% by weight prior to being puffed.
 14. Thepuffed snack product according to claim 1 wherein said puffed starchmaterial body further comprises a plurality of individually puffedkernels of a starch food material.
 15. The snack product according toclaim 14 wherein said puffed kernels comprise at least one of puffedkernels of rice, corn, wheat, rye, oats, millet, sorghum, barley,buckwheat, and mixtures thereof.
 16. The snack product according toclaim 1 wherein said puffed starch material body further comprises astarch powder.
 17. The snack product according to claim 16 wherein thestarch powder comprises at least one of a flour of corn, wheat, potato,oats, rye, barley, and buckwheat, and mixtures thereof.
 18. The snackproduct according to claim 1 wherein said unitary puffed starch bodyfurther comprises corn grits.
 19. The snack product according to claim 1wherein said unitary puffed starch material body further comprisesopposed upper and lower surfaces, wherein at least one of the upper andlower surfaces has a wavy contour and appears as though individualkernels of grain are randomly joined to one another.
 20. A puffed snackproduct comprising: a unitary puffed starch material body composed of astarch material comprising at least one of grain kernels, flour, andpellets formed from a starch powder, and mixtures thereof; and opposedupper and lower surfaces of the starch material body, wherein at leastone of the upper and lower surfaces has a wavy contour and appears asthough individual kernels of grain are randomly joined to one another.21. The puffed snack product according to claim 20 wherein the wavycontour of said puffed starch material body comprises hills and valley22. The puffed snack product according to claim 20 further comprising aflavoring selected from the group consisting of sour cream, barbeque,cheese, garlic, onion, and mixtures thereof.
 23. The puffed snackproduct according to claim 20 wherein said puffed starch material bodycomprises individual puffed pellets formed from at least one of riceflour, corn flour, wheat flour, potato flour, and mixtures thereof. 24.The puffed snack product according to claim 20 wherein said puffedstarch material body comprises individual puffed kernels of rice, corn,wheat, rye, oats, millet, sorghum, barley or buckwheat, and mixturesthereof.
 25. The puffed snack product according to claim 20 wherein saidpuffed starch material body comprises at least one of rice flour, cornflour, wheat flour, potato flour, and mixtures thereof.
 26. The puffedsnack product according to claim 20 further comprising corn grits. 27.The puffed snack product according to claim 20 wherein said puffedstarch material body comprises a mixture of pellets, kernels, and flour.28. The puffed snack product according to claim 20 wherein the puffedstarch material body comprises a mixture of pellets and kernels.
 29. Thepuffed snack product according to claim 20 wherein the puffed starchmaterial comprises a mixture of pellets and flour.
 30. The puffed snackproduct according to claim 20 wherein the puffed starch materialcomprises a mixture of kernels and flour.
 31. The puffed snack productaccording to claim 20 wherein said puffed starch material body includesat least about 51% by weight pellets formed from rice flour.
 32. Thepuffed snack product according to claim 20 wherein each said puffedstarch material body includes at least about 51% by weight pelletsformed from corn flour.
 33. The puffed snack product according to claim20 wherein each said puffed starch material body includes at least about51% by weight puffed rice grains.
 34. The puffed snack product of claim20 wherein said puffed starch material body comprises a generallyregular perimetrical shape.
 35. The puffed snack product according toclaim 34 wherein the perimetrical shape is generally at least one of acircular, triangular, fanciful, and geometric shape.
 36. The puffedsnack product according to claim 20 wherein said puffed snack productcomprises a single layer of puffed starch material.
 37. The puffed snackproduct according to claim 36 wherein the single layer is approximatelyone grain thick.
 38. The puffed snack product according to claim 20wherein said puffed starch product included a moisture content of atleast about 3% by weight prior to being puffed.
 39. The puffed snackproduct according to claim 38 wherein said puffed starch productincluded a moisture content in the range of from about 8% to about 18%by weight prior to being puffed.
 40. The puffed snack product accordingto claim 39 wherein said puffed starch product included a moisturecontent in the range of from about 10% to about 12% by weight prior tobeing puffed.
 41. The puffed snack product according to claim 20 whereinthe puffed snack product is at least one of chips, cakes, and crackers.42. A puffed snack product comprising: a unitary puffed starch materialbody composed of at least two types of starch material selected from thegroup consisting of grain kernels, flour, and pellets, wherein each typeof starch material has been expanded by a different degree; and opposedupper and lower surfaces of the starch material body, wherein at leastone of the upper and lower surfaces has a wavy contour and appears asthough individual kernels of grain are randomly joined to one another.43. The puffed snack product according to claim 42 wherein the puffedstarch material body comprises at least one type of kernel and one typeof pellet.
 44. The puffed snack product according to claim 42 whereinthe puffed starch material body comprises at least one type of kerneland one type of flour.
 45. The puffed snack product according to claim42 wherein the puffed starch material body comprises at least one typeof pellet and one type of flour.
 46. The puffed snack product accordingto claim 42 wherein said puffed starch material body further comprisescorn grits.
 47. The puffed snack product of claim 42 wherein said puffedstarch material body comprises a generally regular perimetrical shape.48. The puffed snack product according to claim 47 wherein theperimetrical shape is generally at least one of a circular, triangular,fanciful, and geometric shape.
 49. A puffed snack product comprising: aunitary puffed starch material body composed of at least one type ofstarch material selected from the group consisting of grain kernels,flour, and pellets, wherein the type of starch material selectedincludes at least two varieties of the starch material, and wherein eachvariety of the selected starch material has been expanded by a differentdegree; and opposed upper and lower surfaces of the starch materialbody, wherein at least one of the upper and lower surfaces has a wavycontour and appears as though individual kernels of grain are randomlyjoined to one another.
 50. The puffed snack product according to claim49 wherein said puffed starch material body comprises at least twovarieties of individual kernels, wherein each variety of kernel has beenexpanded by a different degree.
 51. The puffed snack product accordingto claim 50 wherein said kernels are selected from the group consistingof rice, corn, wheat, rye, oats, millet, sorghum, barley, buckwheat, andmixtures thereof.
 52. The puffed snack product according to claim 49wherein said puffed starch material body comprises at least twovarieties of individual pellets formed from starch powder, wherein eachvariety of pellet has been expanded by a different degree.
 53. Thepuffed snack product according to claim 52 wherein said pellets areselected from the group consisting of rice pellets, puffed wheatpellets, puffed corn pellets, puffed potato pellets, and mixturesthereof.
 54. The puffed snack product according to claim 49 wherein saidpuffed starch material body comprises at least two types of flour,wherein each type of flour has been expanded by a different degree. 55.The puffed snack product according to claim 54 wherein the flour isselected from the group consisting of a flour of corn, wheat, potato,oats, rye, barley, buckwheat, and mixtures thereof.
 56. The puffed snackproduct of claim 49 wherein said puffed starch material body comprises agenerally regular perimetrical shape.
 57. The puffed snack productaccording to claim 56 wherein the perimetrical shape is generally atleast one of a circular, triangular, fanciful, and geometric shape.